People who have grown up sitting cross legged for meals and TV etc find it comfortable.

The article says nothing about sitting crosslegged. The article is about squatting. And it doesn't say the problem affects westerners. Westerners don't spend excessive time squatting. It says populations that spend time squatting have higher incidence of knee and osteoarthritis. The conclusion from this is that while squatting is worse than sitting, it doesn't make sitting healthy either.